Metallica headlined the Reading and Leeds Festivals at the end of August
Metallica's new album Death Magnetic has gone on sale in the UK ahead of its planned release.
The metal band's hotly anticipated 12th album was due out on Friday.
But their record label Vertigo is believed to have told shops to go ahead and sell it early after some retailers broke the sales embargo.
Zavvi's flagship store on London's Oxford Street started selling it on Wednesday, while HMV also said it was now available in its stores.
An HMV spokesman said: "We were advised yesterday by the label that because it's been leaked quite heavily, they should bring forward its physical release and allow retailers to merchandise it.
Glasvegas will battle Metallica for the number one spot
"That was the communication we received and we've responded to that. I'd imagine it's a similar picture across the whole of retail."
There is no suggestion that HMV or Zavvi broke the sales embargo.
Music Week magazine reported that more than 2,500 copies of the album had been sold on CD by the end of Wednesday.
A spokeswoman for the band said Friday was still the official release date. Representatives for Vertigo were unavailable to comment.
Death Magnetic may now have the edge in the battle for the number one spot this Sunday.
Its main rival is the self-titled debut album by Glaswegian rockers Glasvegas.
Bookmakers Ladbrokes have made Glasvegas favourites at 4/7, with Metallica at 5/4.